Rong Bian

Experimental Study on Precision Milling of High Volume Fraction SiCP/Al Composites with PCD End Mills

This paper presents an experimental study on precision milling of high volume fraction SiCP/Al composites with single flute polycrystalline diamond (PCD) end mills. Based on a series of tests, the present study is focused on surface roughness of machined surface and tool wear of single flute PCD end mills. The effect of cutting parameters such as feed per tooth (fz) and depth of cut (ap) on the machined surface roughness (Ra) was investigated. Tool wear was also inspected and analyzed by Scanning Electron Microscope (SEM). According to the results of experiment, there is a layer of aluminum covered on the machined surface. This layer of aluminum can improve the machined surface quality. Through the comparsion of surface roughness in different cutting parameters, it can decrease surface roughness (Ra) by means of using very small cutting parameters. Flank wear and chipping are two main kinds of tool wear. The observed wear mechanism of PCD tools is abrasive wear and adhesive wear. The purpose of this study is to provide an experimental result for further investigation on milling of high volume fraction SiCP/Al composites.

Research on Micromechanical Drilling of Micro-Hole Array in PVC Mask

Globalization of the micro manufacturing technology has become a trend. This technology has been widely used in many fields, especially in aerospace field and biological medicine. The electrolytic PVC mask of micro-hole array is difficult to machine because of the high positional accuracy of the micro-hole array, small diameter of the holes and the high requirement of machining quality. This paper studied the influence of workpiece property, optimization of machining parameters, and chips removing in machining of the electrolytic PVC mask using micromechanical drilling. A feasible method with high efficiency is presented.

Micro-Milling of Fully Sintered ZrO2 Ceramics with Diamond Coated End Mills

This work presents an experimental investigation on micro-milling of fully sintered Zirconia (ZrO2) with CVD diamond coated end mills. The experiments were conducted on a Kern MMP 2522 micro-milling centre. Diamond coated WC micro end mills with stiff geometry, are employed. Effects of cutting parameters on surface quality were investigated by means of a mixed full factorial experimental design. Surface roughness was measured by a Talysurf 120L profilometer. Surface topography was examined using a scanning electron microscope. The results show that a smaller feed rate was apt to result lower surface roughness. With the increase of cutting length, brittle damages were observed in some tests.

Research on Tool Wear of PCD Micro End Mill in Machining of ZrO2 Ceramics

This paper presents a study on the tool wear of micro PCD end mill when machining ZrO2 ceramics. The cutting tool used was a self-designed PCD micro end mill with 1 mm in diameter and single flute. Experiments were conducted on a self-developed micro-milling machine tool. The tool wear characters and progress during the groove milling has been observed. The cutting force and machining accuracy of the grooves also have been studied. Based on the results, it is found that tool wear is mainly on the bottom surface; the cutting force increases with the progress of tool wear; tool wear also affect the width of machined grooves due to the decrease of effective tool diameter.

Experimental Investigation on Ductile Mode Micro-Milling of ZrO2 Ceramics with Diamond-Coated End Mills

ZrO2 ceramics are currently used in a broad range of industrial applications. However, the machining of post-sintered ZrO2 ceramic is a difficult task, due to its high hardness and brittleness. In this study, micro-milling of ZrO2 with two kinds of diamond-coated end mills has been conducted on a Kern MMP 2522 micro-milling center (Kern Microtechnik GmbH, Eschenlohe, Germany). To achieve a ductile mode machining of ZrO2, the feed per tooth and depth of cut was set in the range of a few micrometers. Cutting force and machined surface roughness have been measured by a Kistler MiniDynamometer (Kistler Group, Winterthur, Switzerland) and a Talysurf 120 L profilometer (Taylor Hobson Ltd., Leicester, UK), respectively. Machined surface topography and tool wear have been examined under SEM. Experiment results show that the material can be removed in ductile mode, and mirror quality surface with Ra low as 0.02 μm can be achieved. Curled and smooth chips have been collected and observed. The axial cutting force Fz is always bigger than Fx and Fy, and presents a rising trend with increasing of milling length. Tool wear includes delamination of diamond coating and wear of tungsten carbide substrate. Without the protection of diamond coating, the tungsten carbide substrate was worn out quickly, resulting a change of tool tip geometry.

Tool Wear Characters in Micro-Milling of Fully Sintered ZrO2 Ceramics by Diamond Coated End Mills

This work presents an experimental investigation on micro-milling of fully sintered Zirconia (ZrO2) by diamond coated tools. The experiments were conducted on a Kern MMP 2522 micro-milling centre and WC micro end mills, diamond coated by chemical vapour deposition (CVD) and of stiff geometry were employed as cutting tools. The effects of cutting parameters and milling time on tool wear were investigated. The results revealed that the tool wear characters included diamond coating delamination and wear of substrate WC. Both cutting forces and machined surface quality were affected by tool wear with the progress of milling.